As is well known, a dynamic pressure bearing has a dynamic pressure generating portion configured to cause a dynamic pressure action in lubricating fluid such as lubricating oil which is provided in a bearing gap formed with a shaft to be supported. As the dynamic pressure bearing, there have been known a dynamic pressure bearing configured to support only a radial load, a dynamic pressure bearing configured to support only a thrust load, and a dynamic pressure bearing configured to support both the radial load and the thrust load. The dynamic pressure bearing configured to support the radial load has a dynamic pressure generating portion, specifically, a radial dynamic pressure generating portion on an inner peripheral surface thereof. The dynamic pressure bearing configured to support the thrust load has a dynamic pressure generating portion, specifically, a thrust dynamic pressure generating portion on an end surface thereof.
For example, in Patent Literature 1 described below, there is disclosed a procedure of manufacturing the dynamic pressure bearing configured to support the radial load among the various types of dynamic pressure bearings. Specifically, a green compact of raw material powder, which includes metal powder as a main raw material, is formed through compression molding, and at the same time, a dynamic pressure generating portion is formed on an inner peripheral surface of the green compact through die molding. After that, a sintering step of sintering the green compact to obtain a sintered compact and a dimension correcting step of correcting a dimension of the sintered compact are performed. With the above-mentioned procedure, there is no need to provide a separate die which is required when the dynamic pressure generating portion is formed on the sintered compact through die molding (for example, Patent Literature 2) in the dimension correcting step (shaping step) or the like without forming the dynamic pressure generating portion on the green compact through die molding. Thus, there is an advantage in that the dynamic pressure bearing can be manufactured at low cost. The dynamic pressure bearing configured to support the thrust load and the dynamic pressure bearing configured to support both the radial load and the thrust load can also be manufactured through the procedure similar to that of Patent Literature 1.